title: Fungal small RNAs suppress plant immunity by hijacking host RNA interference pathways.
abstract: Botrytis cinerea, the causative agent of gray mold disease, is an aggressive fungal pathogen that infects more than 200 plant species. Here, we show that some B. cinerea small RNAs (Bc-sRNAs) can silence Arabidopsis and tomato genes involved in immunity. These Bc-sRNAs hijack the host RNA interference (RNAi) machinery by binding to Arabidopsis Argonaute 1 (AGO1) and selectively silencing host immunity genes. The Arabidopsis ago1 mutant exhibits reduced susceptibility to B. cinerea, and the B. cinerea dcl1 dcl2 double mutant that can no longer produce these Bc-sRNAs displays reduced pathogenicity on Arabidopsis and tomato. Thus, this fungal pathogen transfers "virulent" sRNA effectors into host plant cells to suppress host immunity and achieve infection, which demonstrates a naturally occurring cross-kingdom RNAi as an advanced virulence mechanism.
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA.
authors.forename: Arne
authors.initials: A
authors.lastname: Weiberg
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Feng-Mao
authors.initials: FM
authors.lastname: Lin
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhao
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Isgouhi
authors.initials: I
authors.lastname: Kaloshian
authors.forename: Hsien-Da
authors.initials: HD
authors.lastname: Huang
authors.forename: Hailing
authors.initials: H
authors.lastname: Jin
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics; D060565:Argonaute Proteins / Q000235:genetics; D020171:Botrytis / Q000235:genetics / Q000472:pathogenicity*; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000276:immunology*; D018551:Solanum lycopersicum / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D034622:RNA Interference; D012331:RNA, Fungal / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D012331:RNA, Fungal; D034741:RNA, Small Interfering